Guanabenz acetate MCQs With Answer offers B. Pharm students a focused, exam-oriented review of guanabenz acetate pharmacology, mechanism of action, clinical uses and safety. This concise introduction covers key topics: guanabenz acetate as a central alpha2-adrenergic agonist, antihypertensive effects, pharmacokinetics, common adverse effects (sedation, dry mouth, bradycardia), dosing considerations, drug interactions and patient counselling. Emphasis is placed on formulation, monitoring, management of overdose and differences from related agents. These MCQs reinforce therapeutic rationale, formulation science and clinical pharmacy aspects to build competence for exams and practice. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary mechanism of action of guanabenz acetate?
- Stimulates beta-1 adrenergic receptors increasing cardiac output
- Stimulates central alpha-2 adrenergic receptors to reduce sympathetic outflow
- Blocks peripheral alpha-1 receptors causing vasodilation
- Inhibits angiotensin-converting enzyme (ACE)
Correct Answer: Stimulates central alpha-2 adrenergic receptors to reduce sympathetic outflow
Q2. Which therapeutic indication is guanabenz acetate primarily used for?
- Type 2 diabetes mellitus
- Essential hypertension
- Epilepsy
- Asthma
Correct Answer: Essential hypertension
Q3. Which is a common adverse effect associated with guanabenz acetate?
- Dry mouth and sedation
- Hyperglycemia and polyuria
- Bronchospasm
- Severe constipation only
Correct Answer: Dry mouth and sedation
Q4. Abrupt withdrawal of guanabenz acetate most commonly risks which complication?
- Rebound hypertension due to sudden increase in sympathetic tone
- Severe hypoglycemia
- Acute renal failure
- Thrombocytopenia
Correct Answer: Rebound hypertension due to sudden increase in sympathetic tone
Q5. Which drug class may antagonize the antihypertensive effect of central alpha-2 agonists like guanabenz?
- Loop diuretics
- Tricyclic antidepressants (TCAs)
- Statins
- Proton pump inhibitors
Correct Answer: Tricyclic antidepressants (TCAs)
Q6. The most appropriate monitoring parameter after initiating guanabenz therapy is:
- Serum potassium weekly
- Blood pressure and heart rate
- Fasting lipid profile
- Serum calcium
Correct Answer: Blood pressure and heart rate
Q7. Which pharmacokinetic property best describes guanabenz acetate?
- Mostly unchanged excreted in feces
- Predominantly metabolized in the liver with renal excretion of metabolites
- Not absorbed orally and given only parenterally
- Eliminated entirely by glomerular filtration without metabolism
Correct Answer: Predominantly metabolized in the liver with renal excretion of metabolites
Q8. A B.Pharm student counselling a patient on guanabenz should advise which of the following?
- Stop the drug suddenly if dizziness occurs
- Avoid driving until you know how the drug affects you due to sedation
- Double the dose if a dose is missed
- Take the medication only when symptomatic
Correct Answer: Avoid driving until you know how the drug affects you due to sedation
Q9. Which formulation is guanabenz acetate commonly available in for clinical use?
- Intravenous infusion only
- Oral tablets
- Transdermal patch
- Inhaler
Correct Answer: Oral tablets
Q10. Which physiologic effect is expected with guanabenz administration?
- Increased peripheral sympathetic tone
- Decreased peripheral vascular resistance and lowered blood pressure
- Bronchodilation via beta-2 activation
- Increased renin secretion
Correct Answer: Decreased peripheral vascular resistance and lowered blood pressure
Q11. Which adverse effect would prompt evaluation for dose reduction or discontinuation?
- Mild headache controllable with acetaminophen
- Marked bradycardia with lightheadedness
- Transient mild nausea resolving in days
- Slight weight gain over months
Correct Answer: Marked bradycardia with lightheadedness
Q12. In a patient on multiple antihypertensives, adding guanabenz increases risk of:
- Hyperkalemia
- Excessive hypotension and syncope
- Hypoglycemia
- Elevated LDL cholesterol
Correct Answer: Excessive hypotension and syncope
Q13. Which laboratory test is most directly impacted by guanabenz therapy?
- Serum creatinine remains unchanged in all patients
- No specific routine laboratory test is required solely for guanabenz, focus is clinical monitoring of BP and HR
- Frequent liver function tests weekly
- Daily complete blood counts
Correct Answer: No specific routine laboratory test is required solely for guanabenz, focus is clinical monitoring of BP and HR
Q14. Which statement about guanabenz and pregnancy is most appropriate for counseling?
- It is the first-line antihypertensive in pregnancy
- Use in pregnancy requires risk-benefit assessment and specialist input
- Safe and recommended without restrictions
- Causes guaranteed fetal malformations
Correct Answer: Use in pregnancy requires risk-benefit assessment and specialist input
Q15. Which is a recommended management step in guanabenz overdose presenting with severe hypotension?
- Immediate oral activated charcoal only
- Supportive care with intravenous fluids and vasopressors as needed
- Administer insulin bolus
- Use calcium channel blockers to reverse effects
Correct Answer: Supportive care with intravenous fluids and vasopressors as needed
Q16. Compared to clonidine, guanabenz is best described as:
- An opioid receptor antagonist
- Another centrally acting alpha-2 agonist with similar clinical effects
- A direct vasodilator acting on smooth muscle potassium channels
- An ACE inhibitor analogue
Correct Answer: Another centrally acting alpha-2 agonist with similar clinical effects
Q17. Which contraindication is most relevant when considering guanabenz therapy?
- Known hypersensitivity to guanabenz
- History of seasonal allergies only
- Mild controlled hypothyroidism
- Myopia
Correct Answer: Known hypersensitivity to guanabenz
Q18. A pharmacology-focused question: activation of central alpha-2 receptors by guanabenz primarily decreases blood pressure by:
- Increasing cardiac contractility
- Reducing sympathetic outflow and decreasing peripheral vascular resistance
- Blocking calcium channels in vascular smooth muscle peripherally
- Enhancing angiotensin II production
Correct Answer: Reducing sympathetic outflow and decreasing peripheral vascular resistance
Q19. Which patient counseling point addresses a common anticholinergic side effect of guanabenz?
- You may experience increased salivation; chew gum to manage
- Dry mouth is common; maintain oral hygiene and sip water
- Expect profuse sweating and plan clothing accordingly
- Report increased tear production immediately
Correct Answer: Dry mouth is common; maintain oral hygiene and sip water
Q20. From a medicinal chemistry perspective, guanabenz belongs to which broad chemical class?
- Guanidine derivatives with centrally acting sympatholytic activity
- Sulfonylureas
- Corticosteroids
- Monoclonal antibodies
Correct Answer: Guanidine derivatives with centrally acting sympatholytic activity
Q21. Which co-prescribed agent could potentiate CNS depression when used with guanabenz?
- Selective serotonin reuptake inhibitors with no sedative effects
- Benzodiazepines or alcohol
- Topical antibiotics
- Vitamin C supplements
Correct Answer: Benzodiazepines or alcohol
Q22. How should guanabenz doses typically be adjusted in elderly patients?
- Start at lower doses and titrate cautiously due to increased sensitivity
- Always give double the adult dose
- No adjustment; elderly tolerate same doses as young adults without monitoring
- Stop other medications immediately before starting guanabenz
Correct Answer: Start at lower doses and titrate cautiously due to increased sensitivity
Q23. Which clinical sign would suggest therapeutic effect of guanabenz in a hypertensive patient?
- Persistently elevated pulse pressure only
- Reduction in systolic and diastolic blood pressure readings
- Progressive weight gain within one hour
- Increase in ankle edema unrelated to blood pressure
Correct Answer: Reduction in systolic and diastolic blood pressure readings
Q24. Which of the following is an expected effect of guanabenz on renin secretion?
- Marked increase in renin activity due to direct stimulation
- Reduction in renin activity secondary to decreased sympathetic tone
- No effect on renin under any condition
- Immediate and sustained suppression to zero
Correct Answer: Reduction in renin activity secondary to decreased sympathetic tone
Q25. For formulation stability, guanabenz tablets are generally stored:
- Frozen at -20°C
- At controlled room temperature, protected from moisture
- Exposed to direct sunlight to maintain potency
- In strongly acidic solutions
Correct Answer: At controlled room temperature, protected from moisture
Q26. Which pharmacodynamic interaction is a concern when combining guanabenz with beta-blockers?
- Increased risk of hyperthyroidism
- Excessive bradycardia and hypotension
- Reduced efficacy of beta-blockers due to receptor upregulation
- Guaranteed arrhythmia induction in all patients
Correct Answer: Excessive bradycardia and hypotension
Q27. In a patient experiencing severe dry mouth from guanabenz, which nonpharmacologic measure is appropriate?
- Avoid any liquids during the day
- Use sugar-free lozenges, frequent sips of water and good oral hygiene
- Initiate high-sugar candies to stimulate saliva
- Brush teeth once weekly only
Correct Answer: Use sugar-free lozenges, frequent sips of water and good oral hygiene
Q28. Which clinical situation would require specialist consultation before continuing guanabenz?
- Uncomplicated mild seasonal allergies
- Pregnancy or planning pregnancy
- Stable corrected myopia
- Intermittent minor headaches
Correct Answer: Pregnancy or planning pregnancy
Q29. Which statement regarding dose titration of guanabenz is correct?
- Rapid escalation to maximum dose on day one is recommended
- Start low and titrate gradually to minimize adverse effects and rebound risks
- Stopping other antihypertensives immediately is mandatory
- No need to monitor blood pressure during titration
Correct Answer: Start low and titrate gradually to minimize adverse effects and rebound risks
Q30. Which counseling point addresses the risk of rebound hypertension when discontinuing guanabenz?
- Discontinue abruptly to avoid side effects
- Taper the dose gradually under medical supervision to reduce rebound hypertension risk
- Replace with over-the-counter cold remedies without consulting prescriber
- Ignore any blood pressure symptoms after stopping
Correct Answer: Taper the dose gradually under medical supervision to reduce rebound hypertension risk

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